45 research outputs found
Thorpe method applied to planetary boundary layer data
Turbulence affects the dynamics of atmospheric processes by enhancing the transport of mass, heat, humidity and pollutants. The global objective of our work is to analyze some direct turbulent descriptors which reflect the mixing
processes in the atmospheric boundary layer (ABL). In this paper we present results related to the Thorpe displacements dT , the maximum Thorpe displacement (dT )max and the Thorpe scale LT , the Ozmidov scale and their time evolution in the ABL during a day cycle. A tethered balloon was used to obtain vertical profiles of the atmospheric physical magnitudes up to 1000m. We discuss the vertical
and horizontal variability and how different descriptors are related to atmospheric mixing
Filtered deterministic waves and analysis of the fractal dimension of the components of the wind velocity
The difficulty in developing models for waves in turbulent flows is a key problem in the analysis of the complexity of turbulence. We present a method to find and filter perturbations that are generated by the flow of deterministic waves from the power spectrum in the atmospheric boundary layer (ABL). The perturbation model proposed assumes that the amplitude and frequency of such waves decay with time exponentially. For illustrative purposes, we apply the technique to three time series of wind velocities obtained with a sonic anemometer. This analytical procedure allows us to filter waves of the proposed structure with a 99% significance level in the power spectrum. We have applied the same method to 540 such wind series, all painting similar results. We then compare the fractal dimension of the original series to those from which the waves have been removed. We find that the fractal dimension of the filtered waves is slightly less than that of the original series. Finally, we consider the fractal dimension of the studied series as a function of the
length-scales and dissipation rate of kinetic energy per unit mass. Our results suggest an increase of fractal dimension with both length-scale and dissipation rate of kinetic energy
Measuring track vertical stiffness through dynamic monitoring
[EN] This paper proposes a methodology for the evaluation of the track condition by means of the measurement of the track stiffness. This magnitude is calculated from vertical acceleration data measured at the axle box of trains during their normal operation. From the corresponding vertical acceleration spectra, the dominant vibration frequencies for each track stretch are identified and the combined stiffness is then determined. Then the stiffness without the contribution of the rail is calculated. The results obtained for a High Speed ballasted track in several track stretches are within the range 120-130 kN/mm, a result consistent with direct stiffness measurements taken during previous studies. Therefore, the proposed methodology may be used to obtain a first insight to the track condition by means of a continuous measurement of the track combined stiffness. This offers an alternative to traditional stationary stiffness measuring devices and might be a useful complement to dedicated continuous monitoring vehicles.Cano, MJ.; MartĂnez FernĂĄndez, P.; Insa Franco, R. (2016). Measuring track vertical stiffness through dynamic monitoring. Proceedings of the Institution of Civil Engineers - Transport. 169(1). doi:10.1680/jtran.14.00081S169
The FEBEX benchmark test: case definition and comparison of modelling approaches
The FEBEX (Full-scale Engineered Barriers Experiment in Crystalline Host Rock) ââin situââ test was installed at the Grimsel Test
Site underground laboratory (Switzerland) and is a near-to-real scale simulation of the Spanish reference concept of deep geological
storage in crystalline host rock. A modelling exercise, aimed at predicting field behaviour, was divided in three parts. In Part A,
predictions for both the total water inflow to the tunnel as well as the water pressure changes induced by the boring of the tunnel
were required. In Part B, predictions for local field variables, such as temperature, relative humidity, stresses and displacements at
selected points in the bentonite barrier, and global variables, such as the total input power to the heaters were required. In Part C,
predictions for temperature, stresses, water pressures and displacements in selected points of the host rock were required. Ten
Modelling Teams from Europe, North America and Japan were involved in the analysis of the test. Differences among approaches
may be found in the constitutive models used, in the simplifications made to the balance equations and in the geometric symmetries
considered. Several aspects are addressed in the paper: the basic THM physical phenomena which dominate the test response are discussed, a comparison of different modelling results with actual measurements is presented and a discussion is given to explain the
performance of the various predictions.Peer Reviewe
Evaluation of IL-1RA, IL-1ÎČ IFN-Îł and CXCL-10 as mediators of damage and hepatic repair in chronic hepatitis and fibrosis progresion
Outcome of COVID-19 in Patients With Autoimmune Hepatitis: An International Multicenter Study
Background and Aims: Data regarding outcome of COVID-19 in patients with autoimmune hepatitis (AIH) are lacking. Approach and Results: We performed a retrospective study on patients with AIH and COVID-19 from 34 centers in Europe and the Americas. We analyzed factors associated with severe COVID-19 outcomes, defined as the need for mechanical ventilation, intensive care admission, and/or death. The outcomes of patients with AIH were compared to a propensity score?matched cohort of patients without AIH but with chronic liver diseases (CLD) and COVID-19. The frequency and clinical significance of new-onset liver injury (alanine aminotransferase > 2 Ă the upper limit of normal) during COVID-19 was also evaluated. We included 110 patients with AIH (80% female) with a median age of 49 (range, 18-85) years at COVID-19 diagnosis. New-onset liver injury was observed in 37.1% (33/89) of the patients. Use of antivirals was associated with liver injury (P = 0.041; OR, 3.36; 95% CI, 1.05-10.78), while continued immunosuppression during COVID-19 was associated with a lower rate of liver injury (P = 0.009; OR, 0.26; 95% CI, 0.09-0.71). The rates of severe COVID-19 (15.5% versus 20.2%, P = 0.231) and all-cause mortality (10% versus 11.5%, P = 0.852) were not different between AIH and non-AIH CLD. Cirrhosis was an independent predictor of severe COVID-19 in patients with AIH (P < 0.001; OR, 17.46; 95% CI, 4.22-72.13). Continuation of immunosuppression or presence of liver injury during COVID-19 was not associated with severe COVID-19. Conclusions: This international, multicenter study reveals that patients with AIH were not at risk for worse outcomes with COVID-19 than other causes of CLD. Cirrhosis was the strongest predictor for severe COVID-19 in patients with AIH. Maintenance of immunosuppression during COVID-19 was not associated with increased risk for severe COVID-19 but did lower the risk for new-onset liver injury during COVID-19.Fil: Efe, Cumali. Harran University Hospital; TurquĂaFil: Dhanasekaran, Renumathy. University of Stanford; Estados UnidosFil: Lammert, Craig. University School of Medicine; Estados UnidosFil: Ebik, Berat. Gazi YaĆargil Education and Research Hospital; TurquĂaFil: Higuera de la Tijera, Fatima. Hospital General de MĂ©xico; MĂ©xicoFil: Aloman, Costica. Rush University Medical Center; Estados UnidosFil: Rıza CalıĆkan, Ali. Adıyaman University; TurquĂaFil: Peralta, Mirta. Latin American Liver Research Educational And Awareness Network; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Gerussi, Alessio. University of Milano Bicocca; Italia. San Gerardo Hospital; ItaliaFil: Massoumi, Hatef. Montefiore Medical Center; Estados UnidosFil: Catana, Andreea M.. Harvard Medical School; Estados UnidosFil: Torgutalp, Murat. UniversitĂ€tsmedizin Berlin; AlemaniaFil: Purnak, Tugrul. McGovern Medical School; Estados UnidosFil: Rigamonti, Cristina. Azienda Ospedaliera Maggiore Della Carita Di Novara; Italia. UniversitĂ del Piemonte Orientale; ItaliaFil: Gomez Aldana, Andres Jose. Universidad de los Andes; ColombiaFil: Khakoo, Nidah. University of Miami; Estados UnidosFil: Kacmaz, HĂŒseyin. Adıyaman University; TurquĂaFil: Nazal, Leyla. ClĂnica Las Condes; ChileFil: Frager, Shalom. Montefiore Medical Center; Estados UnidosFil: Demir, Nurhan. Haseki Training and Research Hospita; TurquĂaFil: Irak, Kader. SBU Kanuni Sultan SĂŒleyman Training and Research Hospital; TurquĂaFil: Ellik, Zeynep MelekoÄlu. Ankara University Medical Faculty; TurquĂaFil: Balaban, Yasemin. Hacettepe University; TurquĂaFil: Atay, Kadri. Mardin State Hospital; TurquĂaFil: Eren, Fatih. Ordu State Hospital; TurquĂaFil: Cristoferi, Laura. University of Milano Bicocca; Italia. San Gerardo Hospital; ItaliaFil: Batibay, Ersin. Harran University Hospital; TurquĂaFil: Urzua, Ălvaro. Universidad de Chile. Facultad de Medicina.; ChileFil: Snijders, Romee. Radboud University Medical Center; PaĂses BajosFil: Ridruejo, Ezequiel. Latin American Liver Research Educational and Awareness Network; Argentina. CerrahpaĆa School of Medicine; TurquĂa. Centro de EducaciĂłn MĂ©dica e Investigaciones ClĂnicas "Norberto Quirno"; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
Evaluation of IL-12 and CXCL-10 in patients with hepatitis C, non-alcoholic fatty liver disease and liver damage for alcohol consumption
Introduction and Objectives: To Compare serum levels of IL-12 and CXCL-10 in different etiologies of liver disease. Materials and methods: A cross-sectional and multicenter study was carried out, including subjects with alcoholism according to criteria WHO, without (OH) and with liver injury (cirrhosis, CiOH) and (Alcoholic Hepatitis, HA); non-alcoholic fatty liver (NAFLD) and chronic Hepatitis C (CHC), diagnosed by clinical, biochemical data. They were compared with subjects control (CT). For determination of IL-12 and CXCL-10 with MultiplexÂź-MERCK©. Statistical analysis by SPSS V.22 using U de Mann Whitney, p<0.05; values expressed as mean ± standard error. Results: Included 20 subjects with NAFLD, 78 CHC, 14 HA, 20 CiOH, 15 OH y 60 CT. IL-12 was found elevated in OH, HA, CHC vs. CT in OH vs. HCc y HGNA (pâ€0.05). CXCL-10 was found elevated in CiOH, HA and CHC vs. CT(pâ€0.050). Discussion: The IL-12 showed elevated levels in subjects with alcohol consumption and CHC vs. CT that activates other cell types involved in inflammation. CXCL-10 is induced by IFN-Îł, was found elevated in CiOH, HA and CHC, exerting their biological effects through CXCR3, including activation of peripheral immune cells and apoptosis. The ratio of IL-12/CXCL-10 in OH increased 4.6 times, ratifying the participation in chronic and continual inflammatory response by alcohol consumption. Conclusions: IL-12 and CXCL-10 have an important role in alcohol-induced liver disease, confirming their contribution to inflammation, being evident CXCL-10 in advanced stages of the disease, by stimulating and favoring the migration of immune cells to the damage sites. Funding: This work was partially financed by CONACyT SALUD-2016-272579 and PAPIIT- UNAM TA200515. Declaration of interest: The authors declare no potential conflicts of interest
Effects of immunosuppressive drugs on COVID-19 severity in patients with autoimmune hepatitis
Background: We investigated associations between baseline use of immunosuppressive drugs and severity of Coronavirus Disease 2019 (COVID-19) in autoimmune hepatitis (AIH). Patients and methods: Data of AIH patients with laboratory confirmed COVID-19 were retrospectively collected from 15 countries. The outcomes of AIH patients who were on immunosuppression at the time of COVID-19 were compared to patients who were not on AIH medication. The clinical courses of COVID-19 were classified as (i)-no hospitalization, (ii)-hospitalization without oxygen supplementation, (iii)-hospitalization with oxygen supplementation by nasal cannula or mask, (iv)-intensive care unit (ICU) admission with non-invasive mechanical ventilation, (v)-ICU admission with invasive mechanical ventilation or (vi)-death and analysed using ordinal logistic regression. Results: We included 254 AIH patients (79.5%, female) with a median age of 50 (range, 17-85) years. At the onset of COVID-19, 234 patients (92.1%) were on treatment with glucocorticoids (n = 156), thiopurines (n = 151), mycophenolate mofetil (n = 22) or tacrolimus (n = 16), alone or in combinations. Overall, 94 (37%) patients were hospitalized and 18 (7.1%) patients died. Use of systemic glucocorticoids (adjusted odds ratio [aOR] 4.73, 95% CI 1.12-25.89) and thiopurines (aOR 4.78, 95% CI 1.33-23.50) for AIH was associated with worse COVID-19 severity, after adjusting for age-sex, comorbidities and presence of cirrhosis. Baseline treatment with mycophenolate mofetil (aOR 3.56, 95% CI 0.76-20.56) and tacrolimus (aOR 4.09, 95% CI 0.69-27.00) were also associated with more severe COVID-19 courses in a smaller subset of treated patients. Conclusion: Baseline treatment with systemic glucocorticoids or thiopurines prior to the onset of COVID-19 was significantly associated with COVID-19 severity in patients with AIH.Fil: Efe, Cumali. Harran University Hospita; TurquĂaFil: Lammert, Craig. University School of Medicine Indianapolis; Estados UnidosFil: TaĆçılar, Koray. Universitat Erlangen-Nuremberg; AlemaniaFil: Dhanasekaran, Renumathy. University of Stanford; Estados UnidosFil: Ebik, Berat. Gazi Yasargil Education And Research Hospital; TurquĂaFil: Higuera de la Tijera, Fatima. Hospital General de MĂ©xico; MĂ©xicoFil: CalıĆkan, Ali R.. No especifĂca;Fil: Peralta, Mirta. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Gerussi, Alessio. UniversitĂ degli Studi di Milano; ItaliaFil: Massoumi, Hatef. No especifĂca;Fil: Catana, Andreea M.. Harvard Medical School; Estados UnidosFil: Purnak, Tugrul. University of Texas; Estados UnidosFil: Rigamonti, Cristina. UniversitĂ del Piemonte Orientale ; ItaliaFil: Aldana, Andres J. G.. Fundacion Santa Fe de Bogota; ColombiaFil: Khakoo, Nidah. Miami University; Estados UnidosFil: Nazal, Leyla. Clinica Las Condes; ChileFil: Frager, Shalom. Montefiore Medical Center; Estados UnidosFil: Demir, Nurhan. Haseki Training And Research Hospital; TurquĂaFil: Irak, Kader. Kanuni Sultan Suleyman Training And Research Hospital; TurquĂaFil: MelekoÄlu Ellik, Zeynep. Ankara University Medical Faculty; TurquĂaFil: Kacmaz, HĂŒseyin. Adıyaman University; TurquĂaFil: Balaban, Yasemin. Hacettepe University; TurquĂaFil: Atay, Kadri. No especifĂca;Fil: Eren, Fatih. No especifĂca;Fil: Alvares da-Silva, Mario R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Cristoferi, Laura. UniversitĂ degli Studi di Milano; ItaliaFil: Urzua, Ălvaro. Universidad de Chile; ChileFil: EĆkazan, TuÄçe. CerrahpaĆa School of Medicine; TurquĂaFil: Magro, Bianca. No especifĂca;Fil: Snijders, Romee. No especifĂca;Fil: Barutçu, Sezgin. No especifĂca;Fil: Lytvyak, Ellina. University of Alberta; CanadĂĄFil: Zazueta, Godolfino M.. Instituto Nacional de la NutriciĂłn Salvador Zubiran; MĂ©xicoFil: Demirezer Bolat, Aylin. Ankara City Hospital; TurquĂaFil: Aydın, Mesut. Van Yuzuncu Yil University; TurquĂaFil: AmorĂłs MartĂn, Alexandra NoemĂ. No especifĂca;Fil: De Martin, Eleonora. No especifĂca;Fil: Ekin, Nazım. No especifĂca;Fil: Yıldırım, SĂŒmeyra. No especifĂca;Fil: Yavuz, Ahmet. No especifĂca;Fil: Bıyık, Murat. Necmettin Erbakan University; TurquĂaFil: Narro, Graciela C.. Instituto Nacional de la NutriciĂłn Salvador Zubiran; MĂ©xicoFil: Bıyık, Murat. Uludag University; TurquĂaFil: Kıyıcı, Murat. No especifĂca;Fil: KahramanoÄlu Aksoy, Evrim. No especifĂca;Fil: Vincent, Maria. No especifĂca;Fil: Carr, Rotonya M.. University of Pennsylvania; Estados UnidosFil: GĂŒnĆar, Fulya. No especifĂca;Fil: Reyes, Eira C.. Hepatology Unit. Hospital Militar Central de MĂ©xico; MĂ©xicoFil: HarputluoÄlu, Murat. InönĂŒ University School of Medicine; TurquĂaFil: Aloman, Costica. Rush University Medical Center; Estados UnidosFil: Gatselis, Nikolaos K.. University Hospital Of Larissa; GreciaFil: ĂstĂŒndaÄ, YĂŒcel. No especifĂca;Fil: Brahm, Javier. Clinica Las Condes; ChileFil: Vargas, Nataly C. E.. Hospital Nacional Almanzor Aguinaga Asenjo; PerĂșFil: GĂŒzelbulut, Fatih. No especifĂca;Fil: Garcia, Sandro R.. Hospital Iv VĂctor Lazarte Echegaray; PerĂșFil: Aguirre, Jonathan. Hospital Angeles del Pedregal; MĂ©xicoFil: Anders, Margarita. Hospital AlemĂĄn; ArgentinaFil: Ratusnu, Natalia. Hospital Regional de Ushuaia; ArgentinaFil: Hatemi, Ibrahim. No especifĂca;Fil: Mendizabal, Manuel. Universidad Austral; ArgentinaFil: Floreani, Annarosa. UniversitĂ di Padova; ItaliaFil: Fagiuoli, Stefano. No especifĂca;Fil: Silva, Marcelo. Universidad Austral; ArgentinaFil: Idilman, Ramazan. No especifĂca;Fil: Satapathy, Sanjaya K.. No especifĂca;Fil: Silveira, Marina. University of Yale. School of Medicine; Estados UnidosFil: Drenth, Joost P. H.. No especifĂca;Fil: Dalekos, George N.. No especifĂca;Fil: N.Assis, David. University of Yale. School of Medicine; Estados UnidosFil: Björnsson, Einar. No especifĂca;Fil: Boyer, James L.. University of Yale. School of Medicine; Estados UnidosFil: Yoshida, Eric M.. University of British Columbia; CanadĂĄFil: Invernizzi, Pietro. UniversitĂ degli Studi di Milano; ItaliaFil: Levy, Cynthia. University of Miami; Estados UnidosFil: Montano Loza, Aldo J.. University of Alberta; CanadĂĄFil: Schiano, Thomas D.. No especifĂca;Fil: Ridruejo, Ezequiel. Universidad Austral; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones MĂ©dicas e Investigaciones ClĂnicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Wahlin, Staffan. No especifĂca
The Mexican consensus on alcoholic hepatitis
Alcoholic hepatitis is a frequent condition in the Mexican population. It is characterized
by acute-on-chronic liver failure, important systemic inflammatory response, and
multiple organ failure. The severe variant of the disease implies elevated mortality. Therefore,
the AsociaciĂłn Mexicana de GastroenterologĂa and the AsociaciĂłn Mexicana de HepatologĂa
brought together a multidisciplinary team of health professionals to formulate the first Mexican consensus on alcoholic hepatitis, carried out utilizing the Delphi method and resultingin 37 recommendations. Alcohol-related liver disease covers a broad spectrum of patholo-gies that includes steatosis, steatohepatitis, different grades of fibrosis, and cirrhosis and itscomplications. Severe alcoholic hepatitis is defined by a modified Maddreyâs discriminant func-tion score â„ 32 or by a Model for End-Stage Liver Disease (MELD) score equal to or above 21.There is currently no specific biomarker for its diagnosis. Leukocytosis with neutrophilia, hyper-bilirubinemia (>3 mg/dl), AST > 50 U/l ( 1.5-2 can guide thediagnosis. Abstinence from alcohol, together with nutritional support, is the cornerstone oftreatment. Steroids are indicated for severe disease and have been effective in reducing the28-day mortality rate. At present, liver transplantation is the only life-saving option for patientsthat are nonresponders to steroids. Certain drugs, such as N-acetylcysteine, granulocyte-colonystimulating factor, and metadoxine, can be adjuvant therapies with a positive impact on patientsurvival